Ketryn Cornell had worked as an at-will employee at the Berkeley Tennis Club for 15 years when she was fired, she claimed, because new club manager Rigoberto Headley disapproved of her severe obesity.

Cornell claimed that Headley had made offensive remarks about her weight, including once asking her “out of the blue” if she had considered weight-loss surgery. Cornell also said that Headley had humiliated her by ordering new staff uniforms the largest of which was five sizes too small for her. Cornell further claimed Headley paid Cornell less than a thinner, more junior staffer and denied Cornell the opportunity to assume greater responsibilities.

According to the club, Cornell was terminated because she had concealed a running recording device behind the bar in a ballroom where the club’s board was meeting. Recording a private conversation without every participant’s consent is a crime under California law. Headley had discovered and removed the recorder just before the meeting. A board member hid in the ballroom after the meeting and saw Cornell reach into the area where the recorder had been found and then leave.

When confronted, Cornell denied that she had planted the recorder. She claimed she had reached behind the bar after the meeting to find cleaning supplies and left when she did not find any.

Cornell sued the club. In late December, the court of appeal ruled that Cornell was entitled to have most, though not all, of her claims decided by a jury.

Here are key lessons from the court’s 42-page opinion.

Severe obesity may be a legally protected disability. Notwithstanding the recent broadening of the definition of a disability under state and federal law, the court reaffirmed a 1993 California Supreme Court ruling that discriminating against a severely obese employee is unlawful only “if medical evidence demonstrates that it results from a physiological condition affecting one or more of the basic bodily systems,” such as the musculoskeletal or digestive system,“ and limits a major life activity,” such as walking.

An employer need not accommodate a disability of which it is unaware and does not perceive. There was no evidence the club knew or perceived that Cornell’s obvious severe obesity had a physiological cause and therefore qualified as a disability.

An employer must believe the reason it gives for an employee’s termination is true. The court acknowledged the club could reasonably infer that Cornell had planted the recorder. That reasonable belief would have justified ending Cornell’s at-will employment, even if Cornell could show she had not planted the device.

But there also was evidence, said the court, that club officials did not really believe that Cornell had planted the recorder. They knew she had a legitimate reason for checking behind the bar after the meeting and club officials “never fully questioned her about the incident or performed a follow-up investigation.”

If Cornell could show that club officials had no reason to believe that Cornell had planted the recorder when they told other club members that she had, said the court, the club could be liable for defamation.

But establishing the club lied about why it fired Cornell would not be enough to prove discrimination. Cornell also would have to show that a “significant participant” in the decision to fire her was biased. The court concluded that Headley participated in Cornell’s termination and that his comments about her weight in the months before her termination could prove unlawful bias.

Discriminatory actions plus isolated harassing comments may equal unlawful harassment. Hostile environment harassment, based on sex, disability or other protected classification, is unlawful only if it is severe or pervasive. The few weight-related comments Cornell claimed that Headley had made over a number of months did not suffice. But the “official actions” Headley took regarding the uniforms and Cornell’s pay and opportunities could be interpreted by a jury “as enforcing the negative weight-based message his comments conveyed.”

Remember also that an employer can punish harassing conduct by an at-will employee that is not severe or pervasive even where the law cannot.

Dan Eaton is a partner with the San Diego law firm of Seltzer Caplan McMahon Vitek where his practice focuses on defending and advising employers. He also is an instructor at the San Diego State University Fowler College of Business where he teaches classes in business ethics and employment law. He may be reached at eaton@scmv.com. His Twitter handle is @DanEatonlaw.